Field of the Invention
Aspects of embodiments relate to an electrode assembly, and more particularly, to an electrode assembly having a step and having at least two types of electrode unit having different sizes.
Aspects of embodiments relate to a method of manufacturing a battery cell, a battery pack, a device and a battery including the electrode assembly described above.
Description of the Related Art
As the technical development of mobile devices and demand therefor has increased, demand for secondary batteries has also rapidly increased. Particularly, a lithium secondary battery having excellence in terms of energy density, an operating voltage level, management and extended lifespan characteristics has been widely used as an energy source in various electronic products as well as in various mobile devices.
In general, lithium secondary batteries have a structure in which an electrode assembly and an electrolyte are sealed inside battery cases, are largely classified as cylindrical batteries, angular batteries, pouch-type batteries, and the like, according to appearances thereof, and may also be classified as lithium ion batteries, lithium ion polymer batteries, lithium polymer batteries and the like.
In accordance with the recent tendency toward miniaturized mobile devices, demand for thin angular batteries and pouch-type batteries has increased. In particular, interest in lightweight pouch-type batteries has increased.
An electrode assembly accommodated in a battery case may be classified as a jelly-roll type (rolled type) electrode assembly, a stacked type (laminated type) electrode assembly, a laminated and stacked type electrode assembly, or a stacked and folded type (composite type) electrode assembly according to types thereof.
The jelly-roll type electrode assembly is manufactured by coating and pressing an electrode active material on a meal foil used as a current collector plate to be cut to have a band form having a required width and length. Then, a cathode and an anode are partitioned using a separation film to be helically rolled, thereby manufacturing the jelly-roll type electrode assembly. In addition, the stacked type electrode assembly is formed by stacking a cathode, a separation film and an anode in a vertical direction. Further, the composite electrode assembly may be manufactured in a scheme in which a plurality of unit cells including a cathode/a separation film/an anode are disposed on a sheet type separation film and the sheet type separation film is folded such that the unit cells are stacked on one another.
In general, since an electrode assembly according to the related art is manufactured in a scheme in which unit cells having the same size as each other or individual electrodes are stacked, a degree of freedom in terms of shape is considerably reduced, and thus, there are many limits on implementing various designs. Moreover, in order to alter a design, there are many cases in which a relatively complicated and difficult process is required to be undertaken at the time of manufacturing individual electrodes, stacking electrodes of electrical connection.
As such, recent mobile devices have been produced as various types of new product, and therefore, batteries mounted in mobile devices have also been required to have various forms. Accordingly, a new type of electrode assembly in a scheme for easily manufacturing a battery able to be varied to have various forms depending on a form of a device to which a battery cell is to be applied is required to comply with the requirement, based on the form of mobile devices.
An aspect of an embodiment provides an electrode assembly able to be implemented in various designs.
An aspect of an embodiment provides an electrode assembly being light and having excellent electrical capacitance characteristics.
An aspect of an embodiment provides a battery cell, a battery pack and a device including an electrode assembly according to an aspect of the inventive concept.